Clinical and radiological features of cerebral amyloid angiopathy-related inflammation.

Objectives: We want to report the clinical and radiological features of our cohort of patients diagnosed with cerebral amyloid angiopathy-related inflammation (CAA-RI) according to the Boston Criteria and additionally to disclose some atypical clinical characteristics observed in some of them to provide more knowledge about this novel entity.

Methods: We describe 5 patients with probable CAA-RI according to a validation study of proposed criteria for the diagnosis of CAA-RI at University Hospital Josep Trueta of Girona. We consider some clinical characteristics which include the response to immunotherapy, CSF findings, and MRI features. The patient's neurologic outcomes were assessed using the modified Rankin Scale (mRS).

Results: We collected 5 patients admitted for probable CAA-RI. Most were women and the median age was 72 years. The median mRS score at the onset of disease was 1. Parietal lobes were most affected clinically as well as radiologically. Two patients had intracranial hemorrhage. Decreased levels of CSF amyloid beta 42 and 40 protein were observed. Corticosteroids were used in four patients and a remarkable improvement was observed in all of them.

Conclusions: CAA-RI is a condition that predominantly affects parietal lobes according to our case series and this involvement seems to be directly related to a greater burden of microbleeds, cortical siderosis, WMH, and lobar hemorrhages on these lobes. Decreased levels of CSF amyloid beta protein plus increased total tau protein should be considered as part of the diagnostic criteria of CAA-RI. We recommend corticosteroids using, as they have been demonstrated to be very effective in managing CAA-RI.